in oklahoma i get $1.75 to $2.00 per cubic yard of dirt moved in most cases. most 1/2 acre ponds probably average $3,000 or less here. it all depends on whether or not i'd be nervous about the gravel. if i could dig thru it to a suitable material then no problem. the spring probably travels thru that gravel downhill but if you can dig thru it in the core to suitable soil then you can stop the flow at your core which would contain the spring to the pond on the downhill side. if this ditch you speak of goes uphill quickly from pond site you might be in luck. i'd also dig down in the upper part of the pond to see if the spring is flowing there. we call it spring chasing we are trying to establish were its coming from to make sure we can contain it in the pond. here they are like underground streams traveling thru sand or gravel i dont know about there. it may even be coming in from the sides but as long as the pond is lower than the source your fine. if i couldnt find the source its coming from i'd be very nervous. sometimes they seem to come straight up out of the ground if this is the case we move downhill to where the spring is at desired water level of pond or higher. good luck
